Summary of Significant Accounting Policies (Details) (USD $)	3 Months Ended
	Nov. 30, 2012	Aug. 31, 2011
Accounting Policies [Abstract]
Number of Days Used To Determine Short Term Highly Liquid Investments Treatment As Cash Equivalents	90 days
Book Overdrafts	$ 30,000,000	$ 38,000,000
Cash, FDIC Insured Amount	250,000
Customer Issued Letters Of Credit	$ 54,000,000	$ 37,000,000